Backpack



FIG. 1 is a front perspective view of a backpack showing our new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a top view in an open position thereof.

The broken lines shown on the surface of the backpack throughout the views, are understood to represent stitching. 

We claim the ornamental design for a backpack, as shown and described. 